Select the Driving tab so that you can choose a locomotive to drive. You must select a locomotive on the driving tab if you
want to drive it and also if you want to adjust its configuration variables on the tuning tab.
Selecting the Locomotive
Locomotives are chosen for driving on the Drive: drop-down selector. Only locos that are Available are displayed.
are also displayed. If a locomotive is not powered up, it will not be displayed
because it is not available. In addition locomotives that are in consists and also coupled cannot be chosen for separate driving.
However a locomotive may be included in one or more consists and will still be available for separate driving if it is not coupled in
any of its consists.
Control of Locomotive Lights
The currently available products from WifiTrax provide control of the front and rear lights of the locomotive. Each of these may be in three
states: Off, On and Auto. Off means the light is always off, On means it is always on and Auto means that the front or rear light will come on
if the locomotive is driven in that direction. Tap or click the buttons to move through the three states. The lights can be changed while the locomotive
is in motion.
Control of Locomotive Direction
Tapping the Direction button switches between forward and backwards. The direction button is disabled while the locomotive is in motion.
For a multiple unit consist, the direction button applies to the entire consist. It will take into account that some locomotives are facing backwards
provided those locos have been set with reverse direction on the consist tab.
Locomotive Driving Mode
The Driving Mode button can be set to Switching or Main Line. In Switching mode it is possible to control the locomotive more precisely at low speed and the
top speed is limited to about 15 MPH. In Main Line mode, the top speed is as fast as the locomotive can go but there is still a non-linear response at low speeds
to allow for smooth take-offs.
The locomotive can be stopped immediately by clicking or tapping the stop button. The stop button can be used any time. There may be a delay of about a second
before the command reaches the locomotive due to network delay. The locomotive will also take time to stop due to its physical momentum - i.e. the momentum of its
flywheels and body mass.
The speed of the locomotive is controlled by the Speed Lever. There are two modes of use. With Auto Drive turned off,
the speed of the locomotive can be changed by sliding the thumb pad up or down. If the thumb pad is moved fully down, the locomotive will stop
completely. As explained in the Locomotive Driving Mode section, the maximum speed will be governed by whether the
locomotive is set to Switching or Main Line.
Tapping the region above or below the thumb pad will cause the speed to be increased or decreased by an amount determined by the
Tap Amount setting in the General page of the Settings tab.
Auto Drive is a simple feature that allows you to initiate a smooth change of speed of the locomotive. It is turned on or off by clicking or tapping
the Auto Drive button. If you turn Auto Drive on, you can tap or click anywhere on the Tap-Up or Tap-Down region on the Speed Lever and, instead of causing an
incremental speed increase, the tap will cause a Target Rectangle to appear at the location of the tap. The speed of the locomotive will then
gradually increase or decrease towards the target speed. Once the target speed has been reached, the locomotive will stay at that speed. If you tap
right at the bottom of the Tap-Down region the locomotive will slow down and stop. The rate at which the locomotive accelerates or decelerates is determined
by the Tap Amount setting on the General Page of the Settings tab. The higher the Tap Amount, the greater the acceleration or deceleration.
If you wish to take manual control of the locomotive before the Auto Drive action is complete, simply touch or move the thumb pad on the speed lever. Turning off
Auto Drive will also end the Auto Drive action. You may turn Auto Drive on or off while the locomotive is in motion.
The speedometer shows the approximate speed the locomotive is moving in either Miles per Hour (MPH) or Kilometers per Hour. The speed is obtained from the back e.m.f.
generated by the motor, passed through a calibration table to give the speed. The accuracy will depend on the characteristics of the locomotive motor and has been set
at the factory for a typical high quality motor such as those fitted in most new locomotives. We intend to allow the user to adjust this in a later version of this App
as part of the tuning process. You can select MPH or KPH on the General page of the Settings tab.
You can switch between Speedometer display and Telemetry display by clicking or tapping the Telemetry button. When the Telemetry display is visible, it shows the
following information which is an indication of how your locomotive is performing:
- MPH - The speed in Miles per Hour
Demand - The requested speed being sent to the locomotive from this App. The demand is like a speed step and is in the range 0 - 1000. So the WifiTrax system
provides a granularity of one part in a thousand - more than you would ever need.
Target Speed - The target speed that the locomotive firmware calculates from the demand. The units are AD N, which is an integer count ranging from 0 to 4095.
For the technical, this is the required output from the 12-bit A/D Converter converting the motor's back e.m.f to a number N.
Measured Speed - The actual speed of the locomotive as measured at the A/D e.m.f. coverter. The units are AD N, which is an integer count ranging from 0 to 4095.
For the technical, this is the actual output from the 12-bit A/D Converter converting the motor's back e.m.f to a number N.
Proportional Range - The speed control algorithm has a feedback term that is proportional to the error between the Target and Measured speed. The amount is different
according to one of three speed ranges (1, 2 and 3). This figure shows the range in which the speed control is operating in.
- Proportional Term - The actual value of the proportional control term generated from the error between the target and measured speed.
- Derivative Term - The speed control algorithm also uses a derivative term, which depends on the rate of change of the error.
Integral Term - The speed control algorithm also uses an integral term. The purpose of this is to gradually include a fixed error correcting
amount so that the proportional term will reduce to zero.
- Duty Cycle - The duty cycle of the pulse width modulated current passing through the motor. When this is 100%, the locomotive can go no faster.
- Keep Alive - The percentage of full voltage available from the power maintenance capacitors. This will drop if you go over dirty track.
- Motor Current - The average current passing through the motor, measured in Amperes.
Current Limit Events - A number representing the number of times the current has been limited during approximately the last second. Current limiting
is a feature available as part of the locomotive tuning.
Dual Driving Mode
When the Driving tab is displayed, you can switch between single and dual mode as needed using the Single/Dual button outlined above.
Tap or click once to go to dual mode, then tap or click again to go back to single mode.
When in dual mode, the driving controls
are duplicated, including the locomotive selector. You can select a different locomotive for each set of controls and drive them
at the same time. There is no restriction on your choice of locomotive except that you cannot choose the same locomotive for both
sets of controls.
The selection on either or both sides can be a multiple unit consist, so you can drive two consists at the same time if you wish.
One restriction is imposed for safety: You cannot go back to single mode if you have a locomotive selected for driving in the right-hand
set of controls. You must deselect the right hand locomotive first. You can switch from single to dual mode while driving a locomotive with
the left-hand set of controls. So you can switch to dual, drive a loco with the right-hand controls for a while, then switch back to single
while continuing to drive with the left hand controls all the time.
In Dual Driving Mode, the setting of the Auto Drive button applies to both sets of controls. You can initiate Auto Drive speed changes
independently but you cannot tap up or down on one while using Auto Drive on the other.